Automatic cut-off plug for electric irons



May15,192s. 1,669,626

B. F. ORDWAY AUTOMATIC CUT-OFF PLUG FOR ELECTRIC IRONS Filed Sent. 9, 1925 Patented May 15, 1928.

UNITED l STATES BENJAMIN FRANKLIN ORDWAY, OF IASADENA, CALIFORNIA.

AUTOMATIC CUT-OFF PLUG FOR ELECTRIC IRONS.

Application filed September, 1925.

The object of this invention is to provide cheap, simple, and eective means for cutting oif the electric current from electric irons to prevent the same `Strom becoming excessively 'over-heated.

' Itis acommon occurrence for the user of anelectric smoothing iron to leave the same on the ironing board while the iron is connected Yto the electric service and such irons 'are likely to be neglected and to become so over-heated as to burn garments, ironing cloths and ironing boards uponwhich the kelectrically connected iron is left, and in Ymanyinstances, destruction by fire, of the building in which the iron became overheated, has resulted.

An object of this invention is to provide cheap, simple and effect-ive means i'or preventing such occurrences, and this IV do by providing an electric 4plug having contacts adapted for 'connection with the terminals of a heating circuit and connections for ter- 1mina'ls of a source of electrical supply; a stationary switch contact adapted to `be connected to one 'of such termina-ls; a movable switch contact adapted to be connected to fthe other terminal; a manually operated switch key to-electrically connect and disconnect the switch contacts; a spring'tending to normally hold the movable switch contact out of contacting position; means adapted to hold the movable switch ccnitact in contacting position; and a Jfuse 4adapted to beheld in thermal Contact with the smoothing iron, and also adapted to hold the movable contact holding means in spring compressing position while the fuse yis in place; said usebeing adapted to be melted and to release the movable Contact when the iron becomes overheated.

' In this connection I have providedv an insulating plug Yhaving a way therein, and

have provided in said way, a slide having y'shoulders at its ends, one of said shoulders being adapted to be spaced from the end ci the linsulating member to hold a springpressed Contact member in` contacting position'while the fusible plug is unfused.

An object of the invention is ready re- Vstoring of the plug to operative condition,

after a fuse has been melted; and in this connection I provide a ytape formed of fusible 'material and blocked otin by creases to form a 'united series of fuses of a size adapted to be used in the plug, so that when Serial No. 55,382.

a fuse has been melted, a new fuse may be broken oii` of the tape and inserted in place.

An advantage of using a tape formed of fusible material is that the same may be wound around or otherwise secured to the electric cord so that it will always be readily available.

An advantage of this invention is that a fuse may be immediately inserted in place by simply detaching the plug from the iron, and the iron may be lett tree to be used until re-heating is required, whereupon the plug may be restored.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

The invention may be applied in various forms with either a revolvable or a sliding key. An illustration of the sliding key form will be sufficient for a clear understanding ot the invention.

The accompanying drawing illustrates the invention with the slide key.

Figure lis a perspective view of a plug constructed in accordance with this invens tion and having a slide key. The plug is shown connected to a smoothing iron.

Fig. 2 is a side elevation ofthe plug shown in Fig. 1 attached to the iron; t-he key is shown in connecting position and a part ot the skirt is brokenfto expose the fuse retained disconnecting bar.

Fig. 3 is a view of the plug as shown in Fig. 2 the insulating cap shown in Fig. 2 being removed to one side to expose the interior parts.

Fig. 4f is a trag-mental view of the plug as shown in Fig. 3, with a fragment of the cap in place and showing the position of parts after the fuse has been melted.

Fig. 5 is a. view of the attaching end of the plug with fuse in place.

Fig. 6 is a section on line 50G, Figs. 2, 3, l and 5 with fuse in place.

Fig. 7 is a view in section on line a, Figs. 2, 3, 4: and with fuse in place.

v Fig. 8 is a fragmental edge viewvot1 a strip ofuses.

Fig. 9 is a :tace view of the strip of fuses.

The electric plug is shown as comprising an insulating shell formed of two members l, 2, in which are mounted contacts-8, 4, adapted to clamp upon the terminals 5, 6 of the heating circuit, not shown, of the iron sov normally held in contacting position by means ot a fuse 13, formed as a block.

14 indicates means 1n the form of a shoulder on a slide 15, sliding in a way 16, and havino' a standard 1'? that has an overhano' 18 to which an arm 19 is iixed b a rivet 20.

A spring 21 is arranged to normally tend to retract the slide 15 when the fuse 13 is not in place between the shoulder 14 and theend otl the shell, the member' 1 ot which is cut away at 22 to form a seat that will prevent the fuse :from beingv moved when the shoulder 14 is held compressed against the same by the tension of the spring 21.

The lead 9 is connected to the arm 19 and the movable Vswitch contact point 12 by means of the binding post 11, and when the fuse 13 is` in place the Contact point 12 is held in the position indicated in Fig. 3, spaced apart-from the spring 24.

25 is a switchrkey iiXed to and operating the conducting member 26 ot the key switch. One end of said conducting member as at 27 is adapted to always be in contact with the Contact spring 24 and lwhen the fuse is in place and the key is drawn out as indiy cated in Fig. 4, the conducting member 26 of theswitch will wedge against the movable switch contact 12, and sliding thereupon will give a good electrical connection from4 the'movable switch contact 12 through the conductor 26, spring 24, and the contact 4 to the terminal 6, thence through the heating circuit, not shown, and the terminal 5 to the lead 8.

When the iron 7 becomes overeheated, that is,-heated beyond the temperature required forironing or other normal use of the heated iron, the heat from such iron will melt the vfuse 13, thus allowing the spring 21 to retract the shoulder. 14 from thermal connection with the iron and will move the movable contact point 12 out of contacting position, so that the electrical circuit is broken irrespective of the connecting position of they key.

The slide 15 is provided with a thumb piece 28 struck up from the l'slide and adapted to serve as a handle for sliding the slide intothe extended position shown in Figs. 2, 3, 6 and 7 so that another fuse may be inserted in place.

Said handle 28 is shown struck out to form a slot 29 through which the screw 30 that holds the two halves 1 and 2 of the insulating shell tegether, extends;

Said screw being screwed into the nut 31. Said screw and nut also serve to hold the hood 32 in position; bolts 33, 34 being also employed in the usual manner to hold the members 1 and 2 together.

yln the form shown, the member 1 of the insulating shell is recessed at'35 to receive the end or" the bolt 36 that holds the spring clips of the contact 4 in place. This recess also forms a seat for said bolt 35 to hold the contact 4 in place.

The point 27 ot the conductor is adapted and arranged to be held in contact with the spring 24, and the point 27 of said conductor is constructed and arranged to be out of contacting position relative to.themovable contact 12 when the key is in position t0 `break the circuit. i

with the use ot the same, and will thus al- Y ways beat hand when needed.

l claim: y

l. The combination with an electric plug tor connecting the heating circuit of an electric iron with a source of electrical supply; of a movable switch contact; means to move such switch contact out of contacting position; and a fuse held in position to be heated bythe iron, and adapted to maintain the movable switch'contact in contacting lposition, and to be melted-by over-heat of the iron; said contact moving means being adapted to move the movable contact from contacting position when the fuse is melted, and manually operated means lto connect and disconnect the circuit through the movable contact. Y Y

2. The combination with an electric plug for heating irons; of a switch and a springoperated slide provided with a shoulder; and a fusible block adapted to be inserted between the shoulder and the plug body and to be brought into position to be fused by the iron when'the iron is over-heated bythe electric current and said spring for said slide being arranged to move the slide Ato open the switch when the block is fused.

3. The combination with an electrical plug having a contact and a spring electrically connected therewith; of a switch conductor adapted to be moved into and out of conducting posit-ion; a movable switchcontact adapted to be moved into andout otcontacting position; a slide adapted to hold a fuse in position to be melted by over-heating by a body vheated by electrical current out of and When in conducting position and to Contact with both the spring and the movable Contact when the movable Contact is in contacting position and the conductor is brought into conducting position. 15

In testimony whereof, I have hereunto set my hand at Los Angeles7 California,

this 31st day of August, 1925.

BENJAMIN FRANKLlN ORDWAY. 

